Optimal rotational speed rotor load reduction control in Coaxial High - Speed helicopter/engine integration system

To satisfy coaxial helicopters' variable rotational speed control requirements, a flight condition feedforward integrated control strategy based on dynamic inversion is proposed. A coaxial high-speed helicopter/engine integration system is developed using the T700 turboshaft engine's high precision mathematical model. An optimal rotational speed flight strategy targeting minimum fuel flow is designed. To solve the rotor load surge caused by this strategy, a boundary protection controller using projection operator theory is proposed. Simulation results show that this control method can track optimal rotor speed, cutting fuel flow by over 8%. The boundary - protection flight controller, designed via projection operator theory, reduces upper and lower rotor loads. In low - speed flight, loads drop by over 11.8% and 12.4% respectively; in transition flight, by over 12% and 6% respectively. Thus, it effectively enables variable - speed flight control and rotor - load reduction for coaxial - helicopter integrated flight - propulsion systems.